Thursday 16 January 2014 18.06 EST
First published on Thursday 16 January 2014 18.06 EST

Mauricio Pochettino has pledged to remain at Southampton until the end of the season, when he will assess his options regarding the final year on his contract as he digested what he called the "heavy blow" of the departure of the chairman, Nicola Cortese, on Wednesday evening.

The manager admitted that he had endured a difficult night, with many thoughts going through his head, as he considered his future at the club without Cortese, the man who placed such faith in him last January when he hired him as a relative unknown.

Cortese left after a breakdown in his relationship with the Southampton owner, Katharina Liebherr, who has taken on the role of nonexecutive chair as she seeks a replacement for Cortese.

Cortese clashed with her on a number of issues but chief among them was his resistance to her family taking a seat on the football club board. Liebherr, who has the final say on all budgets, wanted to take a closer interest in her family's investment.

Pochettino said at the end of last season that his future was inextricably linked to Cortese's continued involvement at St Mary's and there had been fears that the manager would now be ready to walk away; that the project stood to be undermined, with key players also open to new challenges.

Pochettino moved to address the concerns, as he insisted he would stay until the summer at least, and that no player he wanted to keep would depart this month. It is understood that Luke Shaw, the left-back, who has been chased by Chelsea and Manchester United, is happy to remain until the end of the season. Pochettino made no comment on the future of the striker Rickie Lambert, who is a £7m target for West Ham United.

It was easy to feel that several issues had simply been deferred until the summer. Pochettino has his admirers at other clubs, including Tottenham Hotspur, and it will be interesting to see how he works without Cortese and with Liebherr, whom he admitted he had met on only two occasions – the end-of-season party last May and for five minutes before his press conference on Thursday afternoon.

"It's clear that I was thinking about many things, especially in the night [on Wednesday]," Pochettino said. "And it was clear that I was also thinking about my decision at this club. It was a heavy blow to digest so I was thinking about many things. It was difficult to sleep, I am not going to lie. It's a great responsibility to be the manager at this club. And I am fully, 100% decided on staying here until the end of the season and taking the club as high as I can.

"It is normal that we finish the season; then we will see what happens. It's clear that at the end of the season, we will assess the situation at the club and we will decide whether I am to stay another season."

The Southampton manager, Mauricio Pochettino, found it 'difficult to sleep' after the departure of the chairman Nicola Cortese. Photograph: Richard Sellers/Getty Images

Pochettino attempted to clarify the apparent disparity to his comments from last May, when he had said he "would not understand staying in this role if Nicola was not here".

"We were at the end of the season," Pochettino said. "Nicola wanted me to be here for four months and make sure we stayed up and from then on, a new project started. So it's a different situation to what I said before; they are different moments.

"It is normal that my commitment is to the club and the players in the middle of the season. It would make no sense for me to leave this club in the middle of the season. Nobody would understand it and I know that Nicola would not either.

"How long is the future – 10 years or six months? Until the end of the season, I will be manager if the owners want me to be. On my part, I am not of the view that we should sell any player I do not want to sell."

Pochettino was asked what needed to be in place by the summer for him to stay next season. "I don't know, it's too soon to respond to this," he said. "We need time to assimilate everything. We have to try and be calm. We have time to think about this."

Pochettino said he did not know whether Liebherr would attend the club's match at Sunderland on Saturday lunchtime, although he does feel that an owner should be seen by the supporters. Liebherr has kept an extremely low profile since she took over the club from her late father, Markus, in 2010.

"I think it is important that she is visible," Pochettino said. "But it's a personal decision and she is the chairwoman for a reason. She can do as she pleases."